A tyre for vehicle wheels generally comprises a carcass structure including at least one carcass ply having respectively opposite end flaps in engagement with respective annular anchoring structures, generally referred to as “bead cores”, integrated into the regions usually identified as “beads”, having an inner diameter substantially corresponding to a so-called “fitting diameter” of the tyre on a respective mounting rim. The tyre further comprises a crown structure including at least one belt strip placed at a radially external position to the carcass ply, and a tread band radially external to the belt strip. A so-called “under-layer” of elastomeric material can be interposed between the tread band and the belt strip/s, which under-layer has properties adapted to ensure steady union of the belt strip/s with the tread band. In addition, respective sidewalls of elastomeric material are applied onto the side surfaces of the carcass structure, each extending from one of the side edges of the tread band to close to the respective annular anchoring structure to the beads. In tyres of the “tubeless” type, the carcass ply is internally coated with a layer of preferably butyl-based elastomer material usually referred to as “liner”, which has optimal airtightness features and extends from one of the beads to the other.
It should be pointed out, to the aims of the present specification and the following claims, that the term “elastomeric material” is understood as indicating a composition comprising at least one elastomeric polymer and at least one reinforcing filler. Preferably, this composition further comprises additives such as a cross-linking agent and/or a plasticiser, for example. Due to the presence of the cross-linking agent, this material can be cross-linked through heating, so as to form the final article of manufacture.
In the present specification and the following claims, the term “component” of the tyre means any functional component of the tyre (such as, for example, under-liner, liner, carcass ply/plies, fillers in the bead region, belt layer/s, sidewalls, sidewall inserts in run-flat tyres, abrasion-proof inserts, under-layer, tread band, textile or metallic reinforcing elements, reinforcing elements of elastomeric material, etc.) or a portion thereof.
In the present specification and in the appended claims, the term “semifinished product” means an elongated element, of elastomeric material alone or comprising other structural elements, distributed on a forming drum to form a tyre component.
The semifinished product is preferably defined by a continuous elongated element in the form of a strip. Preferably, said semifinished product is cut to size and has flattened cross section.
Said semifinished product is made of elastomeric material preferably incorporating one or more textile or metallic reinforcing cords. These textile or metallic reinforcing cords are disposed either parallel to each other in the longitudinal direction of the elongated element itself or inclined to said longitudinal direction.
Said continuous elongated element is preferably circumferentially fed onto a forming drum, from a reel or an extruder for example.
In the present description and in the following claims by “deposition line” it is intended an open path, that is not endless, extending between a first end and a second end.
Preferably said deposition line is a substantially straight path.
In the present specification and in the following claims, the expression “space succession” of “n” deposition locations is understood as indicating the physical positioning of said “n” deposition locations disposed one after the other along the deposition line between the first end and the second end, in which each deposition location except the final ones (i.e. the first and last ones) is adjacent to two different deposition locations, a preceding one and a following one, the first deposition location being adjacent to and preceding the second deposition location and the last deposition location being adjacent to and following the last but one deposition location.
Document EP 0 555 813 in the name of the same Applicant shows a plant for manufacturing carcass structures for vehicle wheels comprising a plurality of building drums moved along an assembling path. Each drum, following a predetermined succession, meets a number of primary work stations, each adapted to apply a respective common main component to a plurality of carcass types, alternated with auxiliary work stations adapted to apply accessory components. Each auxiliary work station can be removed and replaced with a different station based on the type of process to be carried out and is movable between a rest position at which it is perpendicularly moved away from the assembling path, and a work position at which it is operatively disposed along the assembling path, to carry out application of the respective accessory component. The primary work stations can be moved close to and away from each other along the assembling path.
Document US 2007/0175567 shows a machine for building tyres comprising a carcass line and a belt/tread line operating simultaneously. Each carcass is joined to a respective belt/tread in an endless assembling line. In the carcass line, building drums are fed in succession along an assembling path through a plurality of stations for component application. In the belt/tread line, cylinders on which the belt/tread package are assembled are fed through further stations for component application. In each component-application station, tyre components used to form parts of the carcass and the belt/tread respectively, are laid on the drum or the cylinder.